Recently prevailing is a function for directly connecting a printer (printing apparatus) with a digital camera (image capturing apparatus) via an interface, e.g., USB, to directly have the printer print a photograph image recorded in a recording medium of the digital camera (e.g., refer to Japanese Patent Application Laid-Open No. 2003-280848). According to this function, it is possible to print a photograph, sensed by a digital camera, without an involvement of a personal computer. Therefore, this function is very effective for a user who is not good at operating a personal computer.
However, currently available printers are considerably inferior to personal computers in terms of CPU processing power. For this reason, in a case where a digital camera is directly connected with a printer to perform printing, the printing speed is lower than the case where printing is performed through a personal computer.
To realize a particularly high-quality color-print image, it is necessary to perform various image processing on image data. In a case where printing is performed through a personal computer, various image processing can be executed by the personal computer. By virtue of this, the printer's processing load is relatively reduced, and even a printer with low CPU processing power can achieve sufficient printing speed. On the contrary, in a case where a digital camera is directly connected with a printer to perform printing, various image processing must be performed by the printer. Since this causes an increased processing load in the printer, sufficient printing speed cannot be achieved by the current printer's CPU processing power.
Furthermore, in keeping with the high resolution trend of currently available digital cameras, the amount of image data is increasing. As a result, not only the processing time of the printer is longer, but also the data transfer time for reading the image data from a digital camera by the printer tends to be increasing. This causes deterioration in printing speed.
To cope with the above problems, for instance, it may be considered to simplify the processing function of the printer to reduce printer's processing load. However, in this case, image quality deterioration will entail in return for reduction of the processing time, and this is not appropriate.
Furthermore, for instance, the amount of image data sensed by a digital camera may be reduced (thinned) before transmitting the image data from the digital camera to the printer for reducing the data transfer time. However, reducing image data without careful consideration results in image quality deterioration; thus, it is not appropriate.